scholarly journals Seed domancy of weedy rice on direct seeded rice fields in Okayama prefecture

2000 ◽  
Vol 45 (Supplement) ◽  
pp. 46-47
Author(s):  
T. Ishii
Keyword(s):  
Rice Fields ◽  
Weedy Rice ◽  
Direct Seeded ◽  
Okayama Prefecture

scholarly journals Cross-Resistance to Imazapic and Imazapyr in a Weedy Rice (Oryza sativa) Biotype Found in Malaysia

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
M. DILIPKUMAR ◽  
N.R. BURGOS ◽  
T.S. CHUAH ◽  
S. ISMAIL
Keyword(s):  
Rice Field ◽  
Rice Cultivar ◽  
Management Tool ◽  
Cross Resistance ◽  
Weedy Rice ◽  
Effective Management ◽  
Herbicide Resistant ◽  
First Case ◽  
Direct Seeded ◽  
Selection Of

ABSTRACT: The Clearfield® rice production system is an effective management tool for weedy rice and other weeds in the direct-seeded rice culture. However, if farmers cultivating the Clearfield® rice disregard stewardship recommendations, the industry could face a problem of herbicide-resistant weedy rice which would occur through the selection of outcrosses. This study aimed to confirm imidazolinone-resistant weedy rice in Malaysia. The resistant weedy rice (R-WR) was found to be 67 fold more resistant to OnDuty® (premix of imazapic and imazapyr) than the susceptible weedy rice (S-WR) based on the GR50 values (rate that causes 50% inhibition of shoot growth). The Clearfield® rice cultivar was 32-fold more tolerant to OnDuty® than the S-WR. Furthermore, the R-WR was 54 and 89 fold more resistant to imazapic and imazapyr applied separately than the S-WR, respectively. The Clearfield® rice was 140- and 40-fold more tolerant to imazapic and imazapyr, respectively than the S-WR. The R-WR biotype was susceptible to non-selective herbicides glyphosate and glufosinate, as well as the selective graminicide quizalofop. Oxadiazon controlled the R-WR biotype, but pretilachlor was ineffective. The present study documented the first case of weedy rice that was cross-resistant to imazapic and imazapyr in Malaysian Clearfield® rice field.

Chemical control of weedy rice in precise hill-direct-seeded rice in South China

2013 ◽  
Vol 13 (1) ◽  
pp. 39-43 ◽  
Author(s):  
Xuefeng Shen ◽  
Xuhua Gao ◽  
A. Egrinya Eneji ◽  
Yong Chen
Keyword(s):  
South China ◽  
Chemical Control ◽  
Weedy Rice ◽  
Direct Seeded

Impact of weedy rice populations on the growth and yield of direct-seeded and transplanted rice

2007 ◽  
Vol 7 (2) ◽  
pp. 97-104 ◽  
Author(s):  
QIAN JIN CAO ◽  
BO LI ◽  
ZHI PING SONG ◽  
XING XING CAI ◽  
BAO-RONG LU
Keyword(s):  
Growth And Yield ◽  
Weedy Rice ◽  
Transplanted Rice ◽  
Direct Seeded

Phenotypic Differentiation between Weedy Rice Populations Associated with their Local Adaptation in Early-and Late-Season Rice Fields

2021 ◽  
Author(s):  
Zhi Wang ◽  
Xiao-Qi Jiang ◽  
Xing-xing Cai ◽  
Qi-Yu Xia ◽  
Bao-Rong Lu
Keyword(s):  
Flowering Time ◽  
Local Adaptation ◽  
Reproductive Traits ◽  
Common Garden ◽  
Rice Fields ◽  
Day Length ◽  
Weedy Rice ◽  
Early Season ◽  
Late Season ◽  
Late Rice

Abstract Background: Temperatures and photoperiods can profoundly affect plant growth and development and play vital roles in the local adaptation of plant species. Weedy rice (Oryza sativa f. spontanea) is a conspecific weed of cultivated rice, and it was found in the same rice fields (sympatry) of early and late rice-cultivation seasons in Leizhou, Guangdong Province of China. Generally, the phenological conditions, such as temperature and photoperiod, are different in the two seasons. Therefore, the early- and late-season weedy rice populations in the same rice fields provide a perfect system for estimating sympatric divergence in plant species. The previous study had demonstrated considerable genetic divergence between the early- and late-season weedy rice populations. Here, we designed in situ common garden experiments to estimate the phenotypical differences between the two-season weedy rice populations and disclose the local adaptation in weedy rice populations associated with their ambient temperature and photoperiod.Results: Distinct air temperature and day length variation patterns were recognized between the early and late rice-cultivation seasons, based on the 10-year historical climate data. More stressful conditions, indicated by low air temperature and long day length, were found for weedy rice growth in the early seasons. Noticeably, significant differences in plant heights, the number of tillers, flowering time, and reproductive traits were detected between the two-season weedy rice populations according to the early-season common garden experiment. The early-season populations showed evident higher plant heights, more tillers, and earlier flowering time than the late-season populations. However, such differences were not detected in the late-season common garden experiment. In addition, evident local adaptation represented by the traits such as plant heights, flowering time, and reproductive traits was only detected in the early-season weedy rice populations. The principal component analysis also showed clear population clusters between the two-season populations using the phenotypical data.Conclusions: This study provided clear evidence of phenotypic differentiation between the sympatric early- and late-season weedy rice populations, probably associated with the local adaptation to their ambient temperature and photoperiod. Our findings also have potential roles in facilitating the design of strategies for effective weedy rice control practices.

Weedy rice: An expanding problem in direct‐seeded rice in the Philippines

2020 ◽  
Vol 20 (2) ◽  
pp. 27-37
Author(s):  
Leylani M. Juliano ◽  
Dindo King M. Donayre ◽  
Edwin C. Martin ◽  
Jesusa C. Beltran
Keyword(s):  
The Philippines ◽  
Weedy Rice ◽  
Direct Seeded

scholarly journals Interactive Effect of Weeding Regimes, Rice Cultivars, and Seeding Rates Influence the Rice-Weed Competition under Dry Direct-Seeded Condition

2020 ◽  
Vol 13 (1) ◽  
pp. 317
Author(s):  
Sharif Ahmed ◽  
M. Jahangir Alam ◽  
Akbar Hossain ◽  
A. K. M. Mominul Islam ◽  
Tahir H. Awan ◽  
...  
Keyword(s):  
Weed Management ◽  
Oryza Sativa L ◽  
Interactive Effect ◽  
Rice Production ◽  
Weedy Rice ◽  
Rice Grain ◽  
Rice Cultivars ◽  
Seeding Rate ◽  
Direct Seeded ◽  
Hybrid Cultivar

Dry direct-seeded rice (Oryza sativa L.), a climate-smart and resource-efficient (labor and water) rice production technology is gaining popularity in many parts of Asian countries; however, weeds are the major constraints for its early establishment and optimum productivity. Chemical weed management is effective, rapid, and also decreases weed management costs in dry direct-seeded rice (DSR) system; however, chemical use for weed management have a negative effect on the environment and also have human health hazards. Therefore, integrated weed management (IWM) is the best option for the sustainability of rice production under the DSR system. Improving competitiveness against weeds, weed-competitive rice cultivars, and high seeding rates were found to be the most promising IWM strategies in DSR. In this context, a field study was conducted to evaluate the weed competitiveness of rice cultivars and seeding rates on the performance of aus rice in dry direct-seeded systems in Bangladesh. Three inbred rice cultivars (CV), namely “BRRI dhan26”, “BRRI dhan48”, and “BRRI dhan55”, and one hybrid cultivar, “Arize” were tested in a seeding rate (SR) of 20, 40, and 80 kg ha−1 under two weeding regimes (WR) of weed-free and partially-weedy. Rice grain yield was strongly affected (p < 0.01) by the interactions of WR, CV, and SR. In weed-free conditions, the yield of all three inbred cultivars was increased up to SR of 40 kg ha−1 and for the hybrid cultivar, up to SR of 20 kg ha−1, and with further increment of SR, there was no yield advantage. Conversely, under partially weedy conditions, the yield of three inbred cultivars increased up to SR of 80 kg ha−1; however, for the hybrid cultivar, this increment was up to SR of 40 kg ha−1 and thereafter, no yield gain. In weedy conditions, the higher SR compensates for the yield losses by increasing the competitiveness of rice with weeds. Across SR, the hybrid cultivar had a significantly (p < 0.01) higher weed competitive index (WCI) than all the inbred cultivars and the highest SR always had a higher WCI.

scholarly journals Weed Control by Suppression Ability of Barley as Cover Crop in Dry Direct Seeded Rice Fields

2010 ◽  
Vol 30 (2) ◽  
pp. 177-182
Author(s):  
Jae-Bok Hwang ◽  
Sung-Tae Park ◽  
Seok-Bo Song ◽  
Ki-Yeoul Jung ◽  
Yong-Hwan Lee ◽  
...  
Keyword(s):  
Weed Control ◽  
Cover Crop ◽  
Rice Fields ◽  
Direct Seeded
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